Learnings from a decade experience of a community-based HIV and STI testing and counseling center in Lisbon - Portugal

Background In the context of an increased number of men who have sex with men (MSM) being diagnosed with HIV infection in many European countries, it became a matter of maximum priority to consider new strategies to monitor and tackle the epidemic. In this scenario, CheckpointLX and a cohort study were projected as a sexual health and research center oriented towards MSM in Portugal. Methods In 2011 CheckpointLX was launched in Lisbon as a community-based center for anonymous and free rapid HIV and other sexually transmitted diseases (STI) testing with a strong component of counseling for sexual health, specially targeted at MSM. In the case of a reactive test, a medical appointment is proposed and scheduled. The Lisbon Cohort of MSM is an ongoing observational prospective study conducted at CheckpointLX. Collected data include sexual behaviors, preventive strategies, and history of STI. Results Until July 2019, 7,351 HIV-negative MSM chose to participate in the Lisbon Cohort of MSM. 3,523 had at least one follow-up visit. The median age was 29 (IQR 25 - 37), and 27% were born in a foreign country, including 15% born in Africa and South America. HIV incidence increased up until 2015, reaching 5 reactive tests per 100 tested annually. There has been a sustained decrease in HIV observed since 2015. The use of HIV prevention tools was provided: 31% used condoms consistently, 3% reported PrEP, and 4% PEP. Conclusions A decade since the beginning of this experience shows positive results, such as increased access and testing. We promoted a stigma-free service that facilitated MSM's and other key population's access to sexual health care. We contribute unique data for assisting in the monitoring of the Dublin Declaration in Portugal.N/

Effects of additives on the activity of a covalently immobilised lipase in organic media

Lipase from Mucor miehei was covalently immobilised onto the graft copolymer poly(ethylene)-g.co-hydroxyethyl methacrylate (PE-g.co-HEMA), partially hydrolysed, via a spacer arm of 1,6-diaminohexane activated with glutaraldehyde. To improve the lipolytic activity of the immobilised lipase (for the synthesis of isoamyl-caprylate, as a model), the effect of several additives was investigated. Polyethylene glycol (PEG), glutaraldehyde, organic solvents and buffers, were added during the immobilisation procedure and their effects are reported and compared with the behaviour of the lipolytic preparation without pre-treatment. An increase of 40-100% in the activity was obtained when small quantities of PEG 2000 and glutaraldehyde (used also as an activator of the spacer arm) were added. The activity had a maximum when the pH of the lipase attachment solution was 7.2 and buffered with phosphate. The effect of the aggregation level of biocatalyst particles on the amount of water retained, as well as the effect of the immobilisation on solid supports on the stability to organic solvents, is also reported.http://www.sciencedirect.com/science/article/B6T3C-3V8CG7H-7/1/f8c9c7095fea93b2ccae17922a1f89d

2D pattern evolution constrained by complex network dynamics

Complex networks have established themselves along the last years as being particularly suitable and flexible for representing and modeling several complex natural and human-made systems. At the same time in which the structural intricacies of such networks are being revealed and understood, efforts have also been directed at investigating how such connectivity properties define and constrain the dynamics of systems unfolding on such structures. However, lesser attention has been focused on hybrid systems, \textit{i.e.} involving more than one type of network and/or dynamics. Because several real systems present such an organization (\textit{e.g.} the dynamics of a disease coexisting with the dynamics of the immune system), it becomes important to address such hybrid systems. The current paper investigates a specific system involving a diffusive (linear and non-linear) dynamics taking place in a regular network while interacting with a complex network of defensive agents following Erd\"os-R\'enyi and Barab\'asi-Albert graph models, whose nodes can be displaced spatially. More specifically, the complex network is expected to control, and if possible to extinguish, the diffusion of some given unwanted process (\textit{e.g.} fire, oil spilling, pest dissemination, and virus or bacteria reproduction during an infection). Two types of pattern evolution are considered: Fick and Gray-Scott. The nodes of the defensive network then interact with the diffusing patterns and communicate between themselves in order to control the spreading. The main findings include the identification of higher efficiency for the Barab\'asi-Albert control networks.Comment: 18 pages, 32 figures. A working manuscript, comments are welcome

Testing the Relation Between the Local and Cosmic Star Formation Histories

Recently, there has been great progress toward observationally determining the mean star formation history of the universe. When accurately known, the cosmic star formation rate could provide much information about Galactic evolution, if the Milky Way's star formation rate is representative of the average cosmic star formation history. A simple hypothesis is that our local star formation rate is proportional to the cosmic mean. In addition, to specify a star formation history, one must also adopt an initial mass function (IMF); typically it is assumed that the IMF is a smooth function which is constant in time. We show how to test directly the compatibility of all these assumptions, by making use of the local (solar neighborhood) star formation record encoded in the present-day stellar mass function. Present data suggests that at least one of the following is false: (1) the local IMF is constant in time; (2) the local IMF is a smooth (unimodal) function; and/or (3) star formation in the Galactic disk was representative of the cosmic mean. We briefly discuss how to determine which of these assumptions fail, and improvements in observations which will sharpen this test.Comment: 14 pages in LaTeX (uses aaspp4.sty). 5 postscript figures. To appear in the Astrophysical Journa

Polichromatic image sensor with microlenses for stereoscopic acquisition

This paper presents the fabrication of microlenses for integration on a stereoscopic image sensor in CMOS technology and a low-cost technology for fabricating optical filters arrays tuned for the primary colors. The material selected for fabricating the microlens was the AZ4562 positive photoresist and the fabrication process explained. Moreover, the fabrication process presented in this paper is for directly printing the optical filters into a transparent flexible substrate (acetate).This work was fully supported by the Portuguese Foundation for Science and Technology under the project FCT/PTDC/EEA-ELC/109936/2009 and R. P. Rocha is supported by the Foundation for Science and Technology financial grant SFRH/BD/33733/2009

PrEP users among Lisbon MSM Cohort participants – A first look after PrEP implementation in Portugal

info:eu-repo/semantics/publishedVersio

Photonic sensors based on flexible materials with FBGs for use on biomedical applications

This chapter is intended for presenting biomedical applications of FBGs embedded into flexible carriers for enhancing the sensitivity and to provide interference-free instrumentation.This work was fully supported by the Algoritmi’s Strategic Project UI 319-2011-2012, under the Portuguese Foundation for Science and Technology grant Pest C/EEI/UI0319/2011

The Earliest Phases of Galaxy Evolution

In this paper we study the very early phases of the evolution of our Galaxy by means of a chemical evolution model which reproduces most of the observational constraints in the solar vicinity and in the disk. We have restricted our analysis to the solar neighborhood and present the predicted abundances of several elements (C, N, O, Mg, Si, S, Ca, Fe) over an extended range of metallicities $[Fe/H] = -4.0$ to $[Fe/H] = 0.0$ compared to previous models. We adopted the most recent yield calculations for massive stars taken from different authors (Woosley & Weaver 1995 and Thielemann et al. 1996) and compared the results with a very large sample of data, one of the largest ever used to this purpose. These data have been analysed with a new and powerful statistical method which allows us to quantify the observational spread in measured elemental abundances and obtain a more meaningful comparison with the predictions from our chemical evolution model. Our analysis shows that the ``plateau'' observed for the [$\alpha$/Fe] ratios at low metallicities ($-3.0< [Fe/H] <-1.0$) is not perfectly constant but it shows a slope, especially for oxygen. This slope is very well reproduced by our model with both sets of yields. This is not surprising since realistic chemical evolution models, taking into account in detail stellar lifetimes, never predicted a completely flat plateau. This is due either to the fact that massive stars of different mass produce a slightly different O/Fe ratio or to the often forgotten fact that supernovae of type Ia, originating from white dwarfs, start appearing already at a galactic age of 30 million years and reach their maximum at 1 Gyr.Comment: 32 pages, 9 figures, to be published in Ap